Not only does the credit bureau max out their password length, you have a small list of available non-alphanumeric characters you can use, and no spaces. Also you cannot used a plused email address, and it had an issue with my self hosted email alias, forcing me to use my gmail address.
Both Experian and transunion had no password length limitations, nor did they require my username be my email address.
Update: I have been unable to log into my account for the last 3 days now. Every time I try I get a page saying to call customer service. After a total of 2 hours on hold I finally found the issue, you cannot connect to Equifax using a VPN. In addition there is no option for 2FA (not even email or sms) and they will hang up on you if you push the issue of their security being lax. Their reasoning for lax security and no vpn usage is "well all of our other customers are okay with this".
Banks aren't much better. Up until just a couple years ago, the Treasury Direct website (to buy bonds/etc from the US Treasury) forced you to use a god damned on-screen keyboard to input your password and the passwords were not case sensitive. I'm pretty sure it also only read the first X number of characters of your input because I recall that people tried typing extra characters after their passwords and it would still accept it as valid, though I could be conflating this with some other archaic site.
You are unable to paste your password into the “confirm password” field. I thought I was going to have to type it in, but Bitwarden’s autofill worked.
The first part I'm sure about because I had to create a bookmark of a line of javascript that would bypass the on-screen keyboard and allow you to autofill the password. It was sometime in the last 3 or 4 years that they finally joined the 1990s and updated it